new egg!!!

Hi
Just wondered if someone could help -- we have four eggs under our broody chicken last night and checked they were there this afternoon but now there are only three under her. I don't want to look too much as she gets quite distressed and growls at us if we get too close. As far as i can tell nothing has been in the chicken house as she has been on them all day ... its just a mystery to us .. I know it sounds daft but could she have eaten or discarded it as it was a different colour from the others that were under her ?

A rat also can and will take an egg out from under a hen, although they will often wait until she gets off the nest. Usually, they will wait until a day or two before they are due to hatch. I have actually seen a rat stealing an egg (don't think I have ever been madder )